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steel-pounder
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sight, line spacing
Feb 11th, 2023 at 1:54pm
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can anybody here tell me how to calculate line spacing on a rear sight staff?  is it dependent on distance between front and rear sights or is it just a given distance?
  
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westerner
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Re: sight, line spacing
Reply #1 - Feb 11th, 2023 at 3:14pm
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Not sure what you're asking. Do you want to know how to read a vernier scale or are you wanting to put custom spaced lines on a sight you're making?
  
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nuclearcricket
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Re: sight, line spacing
Reply #2 - Feb 11th, 2023 at 3:31pm
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If it is a vernier rear sight staff, when you move the elevation one line, (.010") it will move your impact about 1"at 100 yds.. That is with a sight radius of 36". If your sight radius is a little less than that, it will move your impact a little more.
Sam
  
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Re: sight, line spacing
Reply #3 - Feb 11th, 2023 at 4:19pm
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Some time ago I made a new elevator for a Stevens rear sight.  The staff lines are spaced at .050"  and the elevator lines are spaced at .040" according to my notes.  HTH

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Joe
  
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n.r.davis
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Re: sight, line spacing
Reply #4 - Feb 11th, 2023 at 4:21pm
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Under the Gunsmithing section there is a Sticky by GT addressing this process.  I was thinking a person needs to go by the Screw Pitch but if you're going by a Verry-Near pitch don't matter.  Pictures when you get them Scribed if you will.  Good luck!  David
  
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marlinguy
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Re: sight, line spacing
Reply #5 - Feb 11th, 2023 at 4:57pm
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Here's a great video narrated by my late friend Wind as to how to adjust an MVA tang sight. It applies to most any quality tang sight.

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steel-pounder
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Re: sight, line spacing
Reply #6 - Feb 11th, 2023 at 9:50pm
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yeah I can read a vernier scale both on a sight and on a caliper! I am asking how to calculate the line spacing to put on a sight staff that I am making.
Quote:
Some time ago I made a new elevator for a Stevens rear sight.  The staff lines are spaced at .050"  and the elevator lines are spaced at .040" according to my notes.  HTH

Regards,
Joe


thanks Joe this is helpful.

Quote:
If it is a vernier rear sight staff, when you move the elevation one line, (.010") it will move your impact about 1"at 100 yds.. That is with a sight radius of 36". If your sight radius is a little less than that, it will move your impact a little more.
Sam


thank you Sam

Quote:
Under the Gunsmithing section there is a Sticky by GT addressing this process.  I was thinking a person needs to go by the Screw Pitch but if you're going by a Verry-Near pitch don't matter.  Pictures when you get them Scribed if you will.  Good luck!  David


thanks David, I will look that up
  
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GT
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Re: sight, line spacing
Reply #7 - Feb 11th, 2023 at 11:11pm
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SP,
To get to the nuts and bolts of line spacing on your sight, use lines on you staff spaced at .050" and .040" on your traveling block.  The traveling block then gets 6 each marks, "0, 10, 20, 30, 40, and 50".  If you do this and want to get more exact, for what the movement values are, you will have calculate the correction factor.  Sight radius distance (front to rear sight) divided by 34.378 then multiplied by .010 (this is what your movement from mark to mark will be)  and you will have actual MOA.  If you keep your sight radius close to the 34.378 distance on your rifle build +/- 3" you'll determine it's an insignificant amount, especially shooting irons.
I made a sight once and did the math to determine what I needed to have my spacing so each line movement gave me 1  MOA exactly.   My sight radius was 36.2" something, the rewards for the hassle - nothing noticeable.
Give it some thought and put it to paper, it'll make sense.
Greg
  
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steel-pounder
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Re: sight, line spacing
Reply #8 - Feb 12th, 2023 at 11:36am
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GT wrote on Feb 11th, 2023 at 11:11pm:
SP,
To get to the nuts and bolts of line spacing on your sight, use lines on you staff spaced at .050" and .040" on your traveling block.  The traveling block then gets 6 each marks, "0, 10, 20, 30, 40, and 50".  If you do this and want to get more exact, for what the movement values are, you will have calculate the correction factor.  Sight radius distance (front to rear sight) divided by 34.378 then multiplied by .010 (this is what your movement from mark to mark will be)  and you will have actual MOA.  If you keep your sight radius close to the 34.378 distance on your rifle build +/- 3" you'll determine it's an insignificant amount, especially shooting irons.
I made a sight once and did the math to determine what I needed to have my spacing so each line movement gave me 1  MOA exactly.   My sight radius was 36.2" something, the rewards for the hassle - nothing noticeable.
Give it some thought and put it to paper, it'll make sense.
Greg


THANK YOU Greg, that is exactly what I wanted to know. Much appreciated.
  
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Re: sight, line spacing
Reply #9 - Feb 12th, 2023 at 3:47pm
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Now I get it. You want custom spacing just for your particular rifle and sight radius. 

If you can do it, why not.  Smiley
  
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Re: sight, line spacing
Reply #10 - Feb 12th, 2023 at 10:29pm
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3600 inches in 100 yards.If you want 1/4" adjustment divide .25 by 3600.Take this decimal result and multiply by your sight radius.This is the distance between you staff marks.You can work the numbers around to suit. 
I hope this is what you are asking?

FWI- on internal adjustment 3-5/8"  "typical" scope base  spacing .001 equals one minute POI change 

In 7.25" external scope spacing .002 is 1 MOA
  
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steel-pounder
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Re: sight, line spacing
Reply #11 - Feb 13th, 2023 at 10:31am
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Cbashooter wrote on Feb 12th, 2023 at 10:29pm:
3600 inches in 100 yards.If you want 1/4" adjustment divide .25 by 3600.Take this decimal result and multiply by your sight radius.This is the distance between you staff marks.You can work the numbers around to suit. 
I hope this is what you are asking?

FWI- on internal adjustment 3-5/8"  "typical" scope base  spacing .001 equals one minute POI change 

In 7.25" external scope spacing .002 is 1 MOA


thank you very much. 
  
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